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Date: Wed, 09 Nov 2005 17:41:45 -0500
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From: "Bill&Sue" <5zq@cox.net>
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Subject: Re: [LML] Re: antennae
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Hello John,

Yes the MB antenna is quite long. I don't remember exactly,  let's see...a 
marker is 75 mhz and the speed of light is 186,000 miles per second. Soooo 
186,000 miles divided by 75,000,000 is 0.00248 miles, times 5280 is 13.0944 
feet. That's should be the wavelength. The antenna is, I think, a half 
wavelength or about 6 and a half feet or 78 inches. OK Scott, I'm counting 
on you to check me on this.

Mine works well...very well. The problem is that you actually don't want it 
to work that well. You should only receive a marker signal when you're 
almost directly over the transmitter. With mine, I start hearing it a mile 
before and continue hearing it a mile after passing the marker. Way too good 
reception.

Maybe some of the electronic gurus can tell us, but I think that maybe a 1/4 
wave antenna might be a better idea.  Three feet could easily be fit into 
the fiberglass fairing at the wingroot. I've been test flying Jim White's 
IVP and he did just that, but I haven't tested the MB reception yet. Next 
time I fly it, I'll report back with the results.

Bill Harrelson
5zq@cox.net
N5ZQ 320 1,100 hrs
N6ZQ  IV    4.073%


> 4. Marker beacon in the belly running from the baggage compt, under the
> baggage bulkhead into the aft fus.


How long is your MB antenna?  I've seen 42", 68" and 75" as "the
correct length".  Apparently yours works whatever length it is....

Thanks

--
John McMahon  ES #170